Develop New of Efficient Catalysts for Hydrodesulphurization Processes of Fuel Oils

摘要

Hydrodesulphurisation is an important part of the hydrotreating process.More stringent regulations on the quality of fuels bring new requirements to the catalytic processes.The removal of sulphur has become a key issue in the oil refining and this work aims to address several aspects of the process.
　　Current hydrotreatment catalysts are unable to effectively remove theses impurities in sufficient quantities to meet government regulation.The goal of this research is to develop more effective hydrotreatment catalysts for producing ultra clean fuels,possibly zero.
　　In this thesis, has a brief introduction about the catalyst, the description of chemicals used and a brief description of the preparation methods used for the synthesis of catalysts are given as well as techniques used for catalyst characterization.It also describes the devices used and procedure for the HDS reaction and conditions of experiments.NiMo, RuNiMo, LaNiMo and CeNiMo supported on γ-Al2O3.The focus is on desulfurization of Ts, which is considered as most important refractory S-compounds to be desulfurized.
　　The results of catalyst characterization are described and information about the structure and physicochemical properties of the prepared catalysts are described by different techniques such as thermogravimetric analysis (TGA), BET surface area,Powder X-ray diffraction, SEM, and EDX.
　　Catalytic activity of Ts was investigated in continuous flow gas phase fixed bed reactor filled with 1.0g of catalyst at variable temperatures of 250℃, 300℃ and 350℃under atmospheric pressure, In order to compare the performance of the following catalysts RuNiMo/γ-Al2O3, LaNiMo/γ-Al2O3 and CeNiMo/γ-Al2O3 with the traditional NiMo/γ-Al2O3.
　　Based on the results, it was found that the catalytic activity of all catalysts increases as the temperature increases with the time on stream.RuNiMo/γ-Al2O3 in the hydrodesulphurization of Ts is the best catalyst with highest conversion of Ts.It's activity increases with time on stream and temperature of the reaction.Similar trend was obtained over the other catalysts.

目录

声明

ABSTRACT

Contents

Chapter 1 Literature Review

1．1 Introduction

1．1．1 Hydrotreating of Refinery Streams

1．1．2 Different S-compounds Encountered in HDS

1．1．3 S-compounds in Refinery Streams

1．1．4 Reaction Pathway of Model Compound Thiophene (Ts)

1．1．5 Conventional HDS

1．1．6 The S-compounds in Diesel Oil Fractions：Nature and Reactivity

1．1．7 The Mechanism of HDS

1．2 Importance of HDS

1．3 Classification of Desulfurization Technologies

1．4 State of Art for Catalytic and Alternative HDS Processes

1．5 Different Catalysts

1．5．1 Structure of the Oxide Catalyst

1．5．2 Structure of the Sulfide Catalyst

1．5．3 Review of Catalysts

1．5．4 Comparison of CoMo／Al2O3 with NiMo／Al2O3 for HDS of 4，6-DMDBT

1．6 Aim of the Work

Chapter 2 Experimental Method

2．1 Materials Used

2．2 Catalyst Characterization Techniques

2．2．1 Thermogravimetric Analysis (TGA)

2．2．2 Surface Area and Porosity Analysis

2．2．3 Powder X-ray Diffraction

2．2．4 Scanning Electron Microscopy (SEM)

2．3 HDS Activity Measurement

2．3．1 Reaction Studies

2．3．2 Set-up of Gas Chromatography (GC)

2．3．3 Set-up of Total Sulphur Analyser

Chapter 3 Preparation and Characterization of Catalyst

3．1 Preparation of Catalysts

3．1．1 Preparation NiMo／γ-Al2O3 Supported Catalyst

3．1．2．Preparation RuNiMo／γ-Al2O3 Supported Catalyst

3．1．3 Preparation LaNiMo／γ-Al2O3 Supported Catalyst

3．1．4 Preparation CeNiMo／γAl2O3 Supported Catalyst

3．2 Catalyst Characterization

3．2．1 Thermogravimetric Analysis (TGA)

3．2．2 Surface Area and Porosity Studies

3．2．3 Powder X-ray Diffraction

3．2．4 Scanning Electron Microscopy (SEM)

Chapter 4 HDS Experiments Evaluation

4．1 HDS of Ts over NiMo／γ-Al2O3

4．2 HDS of Ts over RuNiMo／γ-Al2O3

4．3 HDS of Ts over LaNiMo／γ-Al2O3

4．4 HDS of Ts over CeNiMo／γ-Al2O3

4．5 Activity of the Catalysts at Variable Temperatures with the Time-on-Stream

4．5．1 Activity of the Catalysis After 60 min of Time-on-Stream Under Variable Temperatures

4．5．2 Activity of the Catalysts After 120 min of Time-on-Stream Under Variable Temperatures

4．5．3 Activity of the Catalysts After 180 min of Time-on-Stream Under Variable Temperatures

4．5．4 Activity of the Catalysts After 240 min of Time-on-Stream Under Variable Temperatures

4．5 Conclusion

Chapter 5 Conclusion and Recommendations

5．1 Conclusion

5．2 Recommendations

References

Acknowledgements